Immunotherapy Strategies

Three types of treatments being studied, developed and tested at Princess Margaret Cancer Centre:

Revolutionizing Cancer Therapy

Immunotherapy is rapidly gaining recognition for its potential to change the way we treat cancer and to join chemotherapy, radiation and surgery as a fourth pillar of cancer treatment.

Within the international scientific community, it has been long understood that the immune system has the ability to conquer cancer.

We’re now at a point where this knowledge has started to become translated into treatment possibilities for cancer patients.

We have already seen numerous success stories of cancers fought and lives extended through immunotherapy.

BOOSTING THE ARSENAL

ADOPTIVE T-CELL THERAPY

When the immune system unleashes a response against a threat, it sends the T-cell to do its bidding.

The T-cells are a key part of the immune system’s arsenal, able to attack and kill cancer cells.

In fact, there are T-cells found in tumors that can kill cancer cells. The problem is that there are often not enough of them inside a tumor to get the job done.

That’s where adoptive T-cell therapy comes in – it’s a method of boosting the number of T-cells inside a patient. “We’re trying to engineer an immune response by taking cells from a patient and modifying them in such a way, so that they can fight the cancer more effectively,” says Dr. Marcus Butler of Princess Margaret Cancer Centre.

In this type of immunotherapy, T-cell samples are taken from a patient’s tumor and laboratory methods are used to boost their overall numbers and their tumor-fighting abilities. They are then put back into the patient.

This type of immunotherapy has shown good results in patients treated at major cancer centres around the world. The complex technology needed to produce T-cells for clinical use can only be found in comprehensive cancer centres like The Princess Margaret.

T-CELLS ON ALERT

CANCER VACCINES

The goal of cancer vaccines is to get T-cells to recognize the presence of cancer and fight back.

Dr. Christopher Paige leads a laboratory where cancer cells are genetically modified to make them more visible to the immune system. The modified cancer cells are returned to the body where they activate immune system T-cells which spread throughout the body killing both the modified cancer cells and any other residual cancer cells that are present.

This is considered to be a therapeutic vaccine as it is designed to be used after a cancer has appeared. This is a different concept from vaccines that prevent something from occurring in the first place, such as the vaccine against the human papilloma virus (HPV) that causes cervical cancer.
Other cancer research seeks to stimulate the immune system by using a type of immune cell that helps spur T-cells into action – the dendritic cell. Dendritic cells can be loaded with cancer-specific substances that are recognized by the immune system, triggering an anti-cancer immune response.

UNLEASHING THE IMMUNE SYSTEM

IMMUNE CHECKPOINT BLOCKADE

The immune system has to be able to take on invaders without damaging normal tissue. To do that, it must turn off or limit its attack at key points – scientists call these immune checkpoints.

A type of immunotherapy called immune checkpoint blockade uses drugs to get the immune system to ignore the stop signals at these checkpoints. Conceptually, we think about this as releasing the brakes on the immune system.